Surface　structures　and　physicochemical　properties　critically　influence　osseointegration　of　titanium　(Ti)　implants.　Previous　studies　have　shown　that　the　surface　with　both　micro-　and　nanoscale　roughness　may　provide　multiple　features　comparable　to　cell　dimensions　and　thus　efficiently　regulate　cell-material　interaction.　However,　less　attention　has　been　made　to　further　optimize　the　physicochemical　properties　(e.g.,　crystalline　phase)　and　to　further　improve　the　bioactivity　of　micro/nanostructured　surfaces.　Herein,　micro/nanostructured　titania　surfaces　with　different　crystalline　phases　(amorphous,　anatase　and　anatase/rutile)　were　prepared　and　hydroxyapatite　(HA)　nanorods　were　deposited　onto　the　as-prepared　surfaces　by　a　spin-assisted　layer-by-layer　assembly　method　without　greatly　altering　the　initial　multi-scale　morphology　and　wettability.　The　effects　of　crystalline　phase,　chemical　composition　and　wettability　on　osteoblast　response　were　investigated.　It　is　noted　that　all　the　micro/nanostructured　surfaces　with/without　HA　modification　presented　superamphiphilic.　The　activities　of　MC3T3-E1　cells　suggested　that　the　proliferation　trend　on　the　micro/nanostructured　surfaces　was　greatly　influenced　by　different　crystalline　phases,　and　the　highest　proliferation　rate　was　obtained　on　the　anatase/rutile　surface,　followed　by　the　anatase;　but　the　cell　differentiation　and　extracellular　matrix　mineralization　were　almost　the　same　among　them.　After　ultrathin　HA　modification　on　the　micro/nanostructured　surfaces　with　different　crystalline　phases,　it　exhibited　similar　proliferation　trend　as　the　original　surfaces;　however,　the　cell　differentiation　and　extracellular　matrix　mineralization　were　significantly　improved.　The　results　indicate　that　the　introduction　of　ultrathin　HA　to　the　micro/nanostructured　surfaces　with　optimized　crystalline　phase　benefits　cell　proliferation,　differentiation　and　maturation,　which　suggests　a　favorable　biomimetic　microenvironment　and　provides　the　potential　for　enhanced　implant　osseointegration　in　vivo.　©　2020　The　Authors